Process of inhibiting color decomposition of dyes present in color photographs



Patented Dec. 18, 1951 .menenns;

SI-TIQN E BY-ESQPRESEXIE GDILORZEHQJE E. sewawmaeu Binghamtlrn flilli a si nm- Generals-Aniline & filormration News Yorksmr Yes mtcptnrorationpofi Helm-Wa ez;

NeDrawfim; fivnlicati niAihtl f 3550;. Summer 15.555?- mm. (on. 95 --88) or. browning, of; the color; nhotogga h; stora eis in a heated'.. atmospheres, Another. photographic dyesfdinge condition: ojtenigizesults inn the loss of yellow or other color d'yes; This condi tion is caused by h-i'glttemperature and high humidity; For instance; the storins of colored photographs anattic or evemi-n email-let often produces this-undesirable color*deterioration; It has been determinedthat color prints, pertieue leu'ly the whites, wills-tam" s-filirown' be'oaus or oxidation oftheco1ordeveloping? agent retainell in the subbing layer. and 11-11mm clnmgsi Bnints processed withouth thee, colon clevelop nentg sten do not exhibit this stain. These undesirable; effects, are frequently Qbsemled in; the color photographs? containing azomethine dyes; The; changes naturallszlgmestniot; the;- stotager, condiw tionswhile methqdsoflinciteasing of these dyes to extreme humidity a ndltnesidj 1 chemical fading are of great ,oomme flcial importance.

An object of my-mventlorr lseto provide a noyel method of treating colored photographssm thistxtremehumiditycomlitibns do-mot' dsttomfirifi inalcoloration; u

- Another object of my invehtiom is to obtain color photographs whose colors are stable=- to v 2. wherem-R;;.. R15, andiRa ame thaclass'wonsistizzgsof hydro emandu ww m; suehiasi methyh; ethyl; propyl;v allyli; butyl; and? wherein; Rzri's; alwaysahydrogemwhem Ream? are alkyl;

The; following areexamples of? suitable: m: C which may; be; reacteekAw-ith: formaldehyde:

Urea. N'; Nv=dimethylhnee NT-inethy'luneaj NjN' climethxlnreai.

The tollowlng: compounds; are: illustrative oi; reaction: nzeoduetsv of' formaldehyde: with; uneas which; maybe;- employed; as; stain; inhibltoitsz;

' Bier. was:

(1)) moment 41;. moms 0:04

NHCHzOH N{-methylolrN-,Nedimethyluteas v A'nnslem361; 1551i (5 None 0:04 CmOH' NHQHe Nsmethyloli-N lfli dimethflilmg;

CHEO'H'I', CHr-IG 1.? 03:30? e- FGQ on NN'hllmefiyjnlurfll nndinge maxeexlt: possible twren er Q 1- d'evelopedanultlcolor photographlosmaterial wms memhei*ssselestemsdixurev tically immune to the deteriorative effects of storage or aging while unaffecting the original characteristic graphic materials containing azo, azine, azomethine, indophenol, and quinonimine dyes are substantially improved by subjecting the processed color photographs or; ransparenei s; treatment with aqueous solutions 'ofsaid' add tion products of formaldehyde and ureas. When such solutions are employed,-:as .-final,rinse baths,-...': i. e., after the complete processing of. multicolor) photographic material, they will inhibit-the color- I 1 loss of color photographs which have been ex:

posed to extreme humidity conditions, accelf erated aging, or acidvapors when effecting the original color balance.

fi l h m d 2 g ng; developing multicolor iiphoto The concentration of ithe urea-formaldehyde addition'pr'oductsmay be varied fromasqlittle as; .5 to as muchas Amounts higher than the. latter give'little improvement. Concentrationsranging. between 2 and 5%.,yield satlsfacw tory results. The time of rinsing may also vary,

respective 'of 'whetherl the dyestuff images ;are wgre first ,dewlbpedv for 2 minutes. F. in

produced with color formerspresent inJthe emulsion, ornby a selective second exposure followed by'development with developing solutions con taining color formers'an'd color developing agents;

as color reversible film and the color negative film with the exception that the base consists oi. an -.opa q ue,.white film ,The color paper is also constr'ucte theta eimfannerias the color reversible film and the color negative film, with .;.the exception that the emulsion is coated on a baryta coatedpaperbase. Suitable methods for I of "photographic multilayer madescribed in the literature relating to color photography and are, therefore,

;.-not described, here Multicolonu-photographic materials which are color developedby azine developers, i. e., aromatic triamines, .to yield azine (phenazonium) dye 'imagesarddes'cribed in United States Patent Mul ticblor photographic materials in which the final dye images are azo dye images are preparedaccording ,to the procedural steps disclosed in United-States Patents 1,985,344 and 2,020,775. The following examples'described in detail the methods foraccomplishing the above objects, but

it isto be, understood that they are inserted mere- The color reversible film consists of an integral tripack emulsioncoated on the usual clear cellulose acetate or nitrate film base. Each of the emulsions is sensitized to one of the primary 'colorsbf light, namely blue, green, and red. The top layer is-blue sensitive. yellow in color and blue absorbing, lies under the top layer. Below thisfilter layer, lies a green sensitive emulsion layer, and below this is a red sensitive emulsion'layer; Each of the three silver halide emulsion layers containing dye forming compounds whichunite during the development of a silver ima e in anaromatic amine developing agent to form a dye with the oxidation product of the developing agent, or may be tree from color formers in'which case the film' is processed with the-color formers in the color developers by the selective second exposure and color development method as described in United States Patents 1,897,866, 1,900,870, 1,928,709, and 1,980,941. 7

As silver formed during development, it must be removed after color development by treatment in a bleach, followed by treatment in a bath of sodium thiosulfate, according to usual practice. sensitive emulsion; a magenta dye is formed in the green sensitive' emulsionj-and a' cyan dye is fprmed in the red sensitive emulsion. Combinations of these three printing primaries will pro- A yellow dye is formed in the blue A filter layer,

duce all of the other colors in the finished film tin between the red sensitive layer and the green sensitivelayer." The .color reversible white opaque materialwis; prepared. in the: same manner ly for the purpose of illustration and are notto be construed as-limit-inggthescope of the invention.v

f 1 Example I A 2%" x2% color transparency was printed by' projection on two3"x'5" sheets of color reversible whiteopaque' film having gelatin layers on both sides of the film base. The two exposed color:- reversible white opaque film sheets developer of the followingfcomposition: p-Mononiethylaminophenol sulfate grams 3 Sodium sulfiteu; do 50 H d q mne 6 Sodium carbonate (monohydrate) do 40 Sodium thiocyanate do 2 Potassium bromide. do 2 Water to rnal;eliter 1 l chloride h fl grams 4 s d um,su fii ae g 2 i dm lemme,.h rwh rme ----d 2 Sodium carbonate dO Pot u :b em d e --g+-;-- ----d 1 Water to malre s liter 1 The color =developedjfilm' was rinsed for 4 minutes running water at 68 F. and hardened for 5-minutes-fin a 3% aqueoussolution of potassium chromealum, f- 1,1; I v Th'e hardened as washed ,for' 5 minutes waterfatfifif The washed material was-then treated with a bleach bath of the I01- lowing compositionz V j i petassi 1 05.od um rerrido 15 Disodium phosphate do 40 Sodium bisulfate; do 25 Formalin (40%) cubic centimeters 20 Water to make liter 1 The bleached film was washed for 5 minutes at a brown-yellow in the white areas.

68* F. and then fixed for 5 minutes in a solution of the following composition:

p grams 200 Borax do 10 Water to make liter 1 After fixing, the material was washed for 10 minutes in running water at 68 F.

After the final washing, one print was allowed to dry while the other was rinsed for 3 minutes in an aqueous solution consisting of 98 parts by weight of water and 2 parts by weight of N,N'- dimethylolurea and the print allowed to dry.

Both prints, i. e., the treated and untreated, were exposed to high humidity oven conditions for 5 hours. During that time, the relative humidity in the oven ranged progressively from 56 to 100% at a temperature ranging from 40 to 60 C. The prints were removed from the oven and allowed to reach room temperature. It was observed that a very slight yellowing appeared on the treated color print. The color balance of the untreated color print, however, was completely ruined by a yellow stain appearing overall while at the same time the densities of the original yellow image were lowered. It was also noted that the backs of the treated prints were free of a yellow-brown stain which had appeared on the untreated sample.

Example II Example I was repeated with the exception that the high humidity oven test was replaced by a storage test. Both prints, i. e., the treated and untreated, were stored in an ordinary filing cabinet for over 8 months. Upon inspection, it was noted that the untreated print had stained This brownyellow stain was very noticeable on the back of the untreated print. The images on the treated print had not yellowed nor had the back stained a yellow-brown stain which was so noticeable on the untreated print.

Example III Example I was repeated with the exception that the colored material employed was a color paper and the final rinse bath was a 2% solution of the reaction product of N-ethylurea and formaldehyde (N-methylolmethylenebismonoethylurea) instead of a 2% solution of N,N'-dimethyl- Example IV Example I was repeated with the exception 6 that the final rinse bath was a 3% solution of the reaction product of N,N-dimethylurea and formaldehyde (N'-methylol-N,N-dimethylurea) instead of a 2% solution of N,N'-dimethylolurea.

The untreated film, after being subjected to the high humidity oven test, showed an overall yellow stain and as a result the color balance was completely ruined, whereas the treated film showed no staining whatsoever.

The above specific examples are to be regarded as being merely illustrative of the invention and not in any sense restrictive. It will be obvious to those skilled in the art that many modifications, such as substituting equivalent materials and varying the proportions of the materials used, may be made. The scope of the invention is to be limited solely by the appended claims.

I claim:

1. In a process of producing color photographic images in a multicolor photographic emulsion by exposing the emulsion, color developing, bleaching, fixing and washing the same, the improvement which comprises preventing the formation of stain after the washing operation by rinsing the said colored photographic image with an aqueous solution containing, in an anti-staining amount, a water-soluble addition product of formaldehyde and a urea selected from the class consisting of those having the following formula:

R N I O=C/ e wherein R, R1, and R2 each represent a member selected from the class consisting of hydrogen and lower alkyl, and wherein R2 is always hydrogen whenboth R and R1 are lower alkyl.

2. The process according to claim 1 wherein the addition product is N-methylolurea.

3. The process according to claim 1 wherein the addition product is N,N'-dimethylolurea.

4, The process according to claim 1 wherein the addition product is N-methylolmethylenebismonoethylurea.

5. The process according to claim 1 wherein the addition product is N-methylol-N,N-dimethylurea.

6. The process according to claim 1 wherein the addition product is N-methylol-N,N'-dimethylurea.

E. SCUDDER MACKEY.

No references cited. 

1. IN A PROCESS FOR PRODUCING COLOR PHOTOGRAPHIC IMAGES IN A MULTICOLOR PHOTOGRAPHIC EMULSION BY EXPOSING THE EMULSION, COLOR DEVELOPING, BLEACHING, FIXING AND WASHING THE SAME, THE IMPROVEMENT WHICH COMPRISING PREVENTING THE FORMATION OF STAIN AFTER THE WASHING OPERATION BY RINSING THE SAID COLORED PHOTOGRAPHIC IMAGE WITH AN AQUEOUS SOLUTION CONTAINING, IN AN ANTI-STAINING AMOUNT, A WATERE-SOLUBLE ADDITION PRODUCT OF FORMALDEHYDE AND A UREA SELECTED FROM THE CLASS CONSISTING OF THOSE HAVING THE FOLLOWING FORMULA: 